For the most part the changes are taking the "static propTypes" declaration off
of components and declaring them as Flow types. Sometimes to support flow some
method signatures had to be added. There are some exceptions in which more had
to be done to tame the beast:
- AbstractVideoTrack: put in additional truthy checks for videoTrack.
- Video: add truthy checks for the _videoElement ref.
- shouldRenderVideoTrack function: Some component could pass null for the
  videoTrack argument and Flow wanted that called out explicitly.
- DisplayName: Add a truthy check for the input ref before acting on it.
- NumbersList: Move array checks inline for Flow to comprehend array methods
  could be called. Add type checks in the Object.entries loop as the value is
  assumed to be a mixed type by Flow.
- AbstractToolbarButton: add additional truthy check for passed in type.

* Adds dial in default number and pin to the text for calendar/share.

* Handles fail to fetch numbers or conference id.

For the static page an error message displays stating no room
was specified. On mobile for unsupported browsers, the dial in
info will not show.

- Move the existing components for the static dial in page into
  a separate folder for easier reuse.
- Reuse those components for displaying dial-on numbers on the
  mobile page for unsupported browsers.
- Modify those components to support having tel protocol
  links on the dial-in numbers.
- Have DialInSummary, formerly DialInInfoPage, respect a
  passed in className prop for easier styling differences.

* ref(invite): remove InviteDialog

InviteDialog functionality has been moved into InfoDialog.
The InviteButton has been temporarily hacked to show one
of its dropdown options instead as the button. Future
work will bring in a redesigned InviteModal that the button
will open.

* squash: filter invalid options and map valid options

* squash: update strings

* feat(info): new dialog design

- Add display of a dial in number.
- Add a static page to show a full list of dial in numbers.
- Add password management.
- Invite modal will be changed soon to remove password and
  dial-in.

* squash: add classes for torture tests

* squash: class for local lock for torture tests

* squash: more classes for torture tests

* squash: more classes, work around linter

* squash: remove unused string?

* squash: work around linter and avoid react warnings

* squash: pixel push, add bold

* squash: font size bump

* squash: NumbersTable -> NumbersList

* squash: document response from fetching numbers

* squash: showEdit -> editEnabled, pixel push padding for alignment

* squash: pin -> conferenceID

* squash: prepare to receive defaultCountry from api